Latter



A. A. WOHLAUER,

ELECTRIC LIGHTING uim.

APPLICATION FILED JULY 30, l9l8- 1,368, 74, Patented Feb. 15, 1921.

- INVENTQR Jf/ed A IVM/auer ATTORNEY ALFRED A. WOHLAUER, OF NEW YORK, N. Y.

ELECTRIC-LIGHTING UNIT.

Specification of Letters Patent.

Patented Feb. 15, 1921.

Application filed July 30, 1918. Serial No. 247,351.

V tures.

Li 'hting fixtures. as employed in the art of i1 urnination may be rouped into three general classes; namely, direct, indirect, and semi-indirect, depending upon the class of illumination for which the fixture is intended. Each fixture is constructed to distribute the light in a fixed manner which is pie-determined by the design of the fixture. The principal object of this invention is to provide a lighting unit or distributer which is adapted for use in a lighting fixture and by means of which the light distribution of the fixture may be easily changed at will, without requiring struc tural alteration of the fixture or the use of auxiliary ap liances.

In the lig ting of large ofiice buildings it is desirable to employ a standard and uniform t pe of fixture throughout the entire building. It 1s necessary, however, at times, to vary the light distribution, depending upon the color of the walls and ceilings or upon the use to which the various offices are put. Heretofore this has required the installation of fixtures of different types but with my invention a standard type of fixture can be employed and the required changes in the light distribution can be easily, efficiently and economically effected.

My invention is also applicable to portable standing or table lamps where at certain times it is desired to throw the major flux to the ceiling in order to obtain a general soft illumination, and at other times to direct it downward for reading purposes. I do not attempt to enumerate all of the uses of my invention, as it may be employed in a variety of different ways and combinations, covering practically the whole field of illumination, where it is desired at times to change the direction of the preponderance of the light rays of the light source.

In carrying out my inventlon, I provide a device adapted to inclose the light source, said device being open at both ends and bemg engagcable in the same shade holder a either end. The device is composed of two or more sections each having a distinctive light distributing characteristic, the section adjacent to the shade holder serving to support the other section or sections in either position of the device.

In the accompanying drawings illustratin my invention;

igure '1, is an elevation, partly in section, of a ceiling fixture showing the device engaged at one end in the shade holder.

Fig. 2, is an elevation, on a Smaller scale, of the same fixture showing the device engaged at its other end in the shade holder.

Fig. 3, is an elevation of a standing portable lamp showing the device applied thereto.

Fig. 4, is a fragmentary view of the lamp shown in Fig. 3, withthe device in reversed position.

Fig. 5, is an elevation, partly in section, showing the device in combination with a bowl, and

Fig. 6, is an elevation, partly in section, showing the unit in combination with a reflector.

Referring to the drawings, 1 indicates the distributer composed of a lurality of sections or portions, each having a distinctive light distributing characteristic, and forming a unit which incloses the light source or lamp 2.

The unit is open at both ends and it is arranged to be engaged at either end in the same shade-holder. F or this purpose it is preferably formed with a flange or rim 3 at each end for engagement with the screws or fasteners 4 of the usual shade-holder.

The light distributing characteristic of each section or portion of the unit is determined by its shape and by the material of which it is made. The various sections or portions may be made in any desired shape and of any suitable material, for instance, they may be made of an opaque material or of translucent, mirrored, prismatic, opalescent, or clear glass.

It is essential. however, that the various sections or portions have difi'erent light distributing characteristics, that is to say, that each section or portion shall function to modify or distribute the light in a distinctive manner. For example, in the particular embodiment of the unit illustrated in the drawings, the section or portion is designed and formed to reflect the light; the section (5), consisting of a band of clear glass, to transmit the light; and, the section (0) to diffuse the light. t will be understood that. I do not limit myself to any particular combination of light directing agencies. If desired the unit may be com posed of a combination of mirrored and clear glass, opalescent and mirrored, prismatic and clear, or any other suitable combination.

In the application of the invention shown in Fig. 1, the unit is represented as supported in the shade-holder of a ceiling fixture 5. In the'position shown the unit'acts to direct a preponderance of the light rays toward the ceiling thus producing an indirect or semi-indirect illumination depending upon whether the reflector section (a) is made of opaque or translucent material. Now when it is desired to change the fixture so as to direct the major flux downward or into the lower hemisphere, it is merely necessary to reverse the position of the unit and support it, by its other end in the shadeholder as'shown in Fig. 2. A detachable cap 6 is provided to close the lower end in either.

changed by simply reversing the position of the unit in its holder.

From the foregoing description, it will be apparent to those skilled in the art of illumination, that my invention provides means for readily controlling the direction of the preponderance of light of any fixture.

The term globe as used herein is intended to cover light distributers of other than merely spherical shape. I

What I claim as my inventionand desire to secure by Letters Patent is:

1. An electric lighting unit comprising a light source, a globe supporting member, and an invertible globe surrounding the light source and supportable at either end in said supporting member, said globe being formed of a plurality of sections each having a different light distributing characteristic and whereby, upon inversion of the globe in the support, different distributions be the light are obtained.

7 2. An electric lighting unit comprising alight source, a globe supporting member, and an invertible globe surrounding the light source, said globe having areflecting and a diflusing'portion and being engageable in the support at either of said portions, whereby, upon inversion of'the globe, different distributions of the light are obtained. V v

.3. An electric lighting unit comprising a light source, a globe supporting member, and an invertible globe having a reflector portion and two diametrically opposite openings of substantially equal diameters, said globe being engageable at either opening in the supporting member, whereby, upon inversion of the globe, the preponderance of light flux can be directed upward or downward as desired.

' ALFRED A. WOHLAUER. 

